The present invention relates to a multi-piece solid golf ball composed of a core, an envelope layer, an intermediate layer and a cover that have been formed as successive layers. More specifically, the invention relates to a multi-piece solid golf ball which has a satisfactory flight performance and controllability even when used by professionals and other skilled golfers, and also has a good feel on impact and an excellent scuff resistance.
Key performance features required in a golf ball include distance, controllability, durability and feel. Balls having these qualities in the highest degree are constantly being sought. Among recent golf balls, a succession of balls having multi-piece structures which are typically composed of three pieces have emerged. By having the structure of a golf ball be multilayered, it is possible to combine many materials of different properties, thus enabling a wide variety of ball designs in which each layer has a particular function.
In particular, multi-piece solid golf balls having an optimized hardness relationship among the respective layers encasing the core, such as the intermediate layer and cover, have come into widespread use. Recently, in addition to the flight performance of a ball, the durability of the ball to repeated impact (which inhibits crack formation) and the scuff resistance (which inhibits burr formation on the ball surface) have also become important factors in evaluating ball performance. Therefore, a major challenge is to design the thickness and hardness of the respective ball layers in such a way as to maximize these effects.
With regard to golf balls for professionals and other skilled golfers in particular, there exists a desire for the development of balls in which the thickness and hardness of each layer encasing the core, such as the intermediate layer and the cover layer, have been highly optimized in order to provide the ball with a good feel and excellent durability and to achieve a superior distance performance in the high head speed range as well as precise controllability on shots with an iron and on approach shots.
Golf balls having such a multilayer structure have been disclosed in, for example, JP-A 2009-160407, U.S. Pat. No. 6,302,808, JP-A 2001-017569, JP-A 2001-017570, JP-A 2001-037914, JP-A 2008-149131, JP-A 2009-095365 and JP-A 2009-095369. However, because these lack a sufficient spin rate-lowering effect on full shots, there remains room for improvement in increasing the distance.